Merge pull request #176 from sheffler/fixFirstProgressReport

progress_token is 0 on first tool-call and the return is taken mistakenly

src/mcp/server/fastmcp/server.py

@@ -602,7 +602,7 @@ class Context(BaseModel):
             else None
         )
 
-        if not progress_token:
+        if progress_token is None:
             return
 
         await self.request_context.session.send_progress_notification(